HOW TO MEASURE THE INFLUENCE OF LANDSCAPE ON POPULATION GENETIC STRUCTURE: DEVELOPING RESISTANCE SURFACES USING A PATTERN-ORIENTED MODELING APPROACH

AbstractThere are several approaches to understand how a landscape, with its several components, affects the genetic population structure by imposing resistance to gene flow. Here we propose the creation of resistance surfaces using a Pattern-Oriented Modeling approach to explain genetic differentiation, estimated by pairwise FST, among “Baruzeiro” populations (Dipteryx alata), a tree species widely distributed in Brazilian Cerrado. To establish the resistance surface, we used land use layers from the area in which the 25 “Baruzeiro” populations were sampled, generating 10000 resistance surfaces. To establish the resistance surface, we used land use layers from the area in which the 25 “Baru” populations were sampled, generating 10000 resistance surfaces. We randomized the cost values for each landscape component between 0 and 100. We use these surfaces to calculate pairwise matrices of the effective resistance among populations. Mantel test revealed a correlation of pairwise FST with a geographical distance equal to r = 0.48 (P < 0.001), whereas the Mantel correlations between pairwise FST and the generated resistance matrices ranged between r = −0.2019 and r= 0.6736. Partial regression on distance matrices was used to select the resistance matrix that provided the highest correlation with pairwise FST, based on the AIC criterion. The selected models suggest that the areas with lower resistance are characterized as natural savanna habitats of different forms, mainly arboreal dense savannas. In contrast, roads, big rivers, and agricultural lands cause higher resistance to gene flow.

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Deferring Crisis

10.1093/oso/9780190865177.003.0002 ◽

2018 ◽

Author(s):

Erin Stewart Mauldin

Keyword(s):

Land Use ◽

Environmental Impacts ◽

Shifting Cultivation ◽

Crop Production ◽

Animal Husbandry ◽

Antebellum South ◽

Westward Expansion ◽

The Cost ◽

Land Use Practices ◽

Ecological Regime

This chapter explores the ecological regime of slavery and the land-use practices employed by farmers across the antebellum South. Despite the diverse ecologies and crop regimes of the region, most southern farmers employed a set of extensive agricultural techniques that kept the cost of farming down and helped circumvent natural limits on crop production and stock-raising. The use of shifting cultivation, free-range animal husbandry, and slaves to perform erosion control masked the environmental impacts of farmers’ actions, at least temporarily. Debates over westward expansion during the sectional crisis of the 1850s were not just about the extension of slavery, they also reflected practical concerns regarding access to new lands and fresh soil. Both were necessary for the continued profitability of farming in the South.

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Genetic structure and diversity of the mustard hill coral Porites astreoides along the Florida Keys reef tract

Marine Biodiversity ◽

10.1007/s12526-021-01196-7 ◽

2021 ◽

Vol 51 (4) ◽

Author(s):

Dominique N. Gallery ◽

Michelle L. Green ◽

Ilsa B. Kuffner ◽

Elizabeth A. Lenz ◽

Lauren T. Toth

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Genetic Relatedness ◽

Florida Keys ◽

Genetic Population ◽

High Genetic Diversity ◽

Western Atlantic ◽

Porites Astreoides ◽

Single Well ◽

Reef Tract

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.

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Genetic structure and historical and contemporary gene flow of Astyanaxmexicanus in the Gulf of Mexico slope: a microsatellite-based analysis

PeerJ ◽

10.7717/peerj.10784 ◽

2021 ◽

Vol 9 ◽

pp. e10784

Author(s):

Rodolfo Pérez-Rodríguez ◽

Sarai Esquivel-Bobadilla ◽

Adonaji Madeleine Orozco-Ruíz ◽

José Luis Olivas-Hernández ◽

Francisco Javier García-De León

Keyword(s):

Gene Flow ◽

Gulf Of Mexico ◽

Microsatellite Loci ◽

Evolutionary History ◽

Population Analysis ◽

Morphological Variability ◽

High Capacity ◽

Genetic Population ◽

Contemporary Gene Flow ◽

Taxonomic Uncertainty

Background Astyanax mexicanus from the river basins of the Gulf of Mexico slope are small freshwater fish that usually live in large groups in different freshwater environments. The group is considered successful due to its high capacity for dispersal and adaptation to different habitats, and the species present high morphological variability throughout their distribution in Mexico. This has produced the most extreme morphotype of the group; the hypogeous or troglobite, which has no eyes or coloration, and is probably the cause of taxonomic uncertainty in the recognition of species across the entire range. Most studies of A. mexicanus have mainly focused on cave individuals, as well as their adjacent surface locations, providing an incomplete evolutionary history, particularly in terms of factors related to dispersal and the potential corridors used, barriers to gene flow, and distribution of genetic variability. The aim of the present study is to determine the population structure and the degree and direction of genetic flow in this complex taxonomic group, incorporating geographic locations not previously included in analyses using microsatellite loci. Our aim is to contribute to the knowledge of the intricate evolutionary history of A. mexicanus throughout most of its range. Methods The present study included a set of several cave and surface locations of A. mexicanus, which have been widely sampled along the Gulf of Mexico slope, in a genetic population analysis using 10 microsatellite loci. Results Ten genetic populations or lineages were identified. In these populations, gene flow was recorded at two time periods. Historical gene flow, both inter and intra-basin, was observed among surface populations, from surface to cave populations, and among cave populations, whereas recording of contemporary gene flow was limited to intra-basin exchanges and observed among surface populations, surface to cave populations, and cave populations.

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Reducing the Cost Effects of Local Land Use Controls

Journal of the American Planning Association ◽

10.1080/01944368108977099 ◽

1981 ◽

Vol 47 (2) ◽

pp. 145-153 ◽

Cited By ~ 10

Author(s):

David E. Dowall

Keyword(s):

Land Use ◽

Land Use Controls ◽

The Cost

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Assessment and Prediction of Land Use/Land Cover Changes of Beas Basin Using a Modeling Approach

10.1007/978-3-030-70238-0_20 ◽

2021 ◽

pp. 471-487

Author(s):

Seema Rani ◽

Sreedharan Sreekesh

Keyword(s):

Land Use ◽

Land Cover ◽

Land Cover Changes ◽

Land Use Land Cover ◽

Modeling Approach

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A Nested Land Uses–Landscapes–Livelihoods Approach to Assess the Real Costs of Land-Use Transitions: Insights from Southeast Asia

Land ◽

10.3390/land8010011 ◽

2019 ◽

Vol 8 (1) ◽

pp. 11 ◽

Cited By ~ 2

Author(s):

Guillaume Lestrelin ◽

Jean-Christophe Castella ◽

Qiaohong Li ◽

Thoumthone Vongvisouk ◽

Nguyen Dinh Tien ◽

...

Keyword(s):

Land Use ◽

Land Use Changes ◽

Forest Degradation ◽

Economic Benefits ◽

Opportunity Costs ◽

Costs And Benefits ◽

Wide Range ◽

Forested Areas ◽

Mitigate Climate Change ◽

The Cost

Reducing emissions from deforestation and forest degradation (REDD+) is viewed as an effective way to mitigate climate change by compensating stewards of forested areas for minimizing forestland conversion and protecting forest services. Opportunity costs assess the cost of foregone opportunity when preserving the forest instead of investing in an alternative activity or resource use. This paper questions the calculation method of opportunity costs using averaged economic benefits and co-benefits of different land-use transitions. We propose a nested approach to land-use transitions at the interface between landscapes and livelihoods and assessing a wide range of potential socio-ecological costs and benefits. Combining household surveys and focus groups with participatory mapping, we applied the approach in villages of Laos, Vietnam and China positioned along a broad transition trajectory from subsistence shifting cultivation to intensive commercial agriculture. By looking beyond the economics of land use, we highlight important linkages between land-use changes and livelihood differentiation, vulnerability and inequalities. Our results show the importance of addressing the impacts of land-use transitions on a wide range of potential ecological and socioeconomic costs and benefits at multiple levels.

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